This invention relates to lighting fixtures, and more importantly to fixtures usable for indoor or outdoor lighting and which are adjustable to provide various beam spreads.
A particular lighting fixture type may need to be adjustable to provide various beam spreads to accomplish a given task; e.g., in one location a fixture may require a wide spread to illuminate a specified area and in another location may require more intense illumination over a smaller area. While fixtures are available with some adjustment in beam spreads, a limited number of beam spreads are available.
There is a need for a low cost, compact, metal halide lighting fixture which is suitably sealed to permit outdoor installation and which is adjustable to provide an infinite range of beam spreads from a spotlight to floodlight, while maintaining a relatively uniform intensity across the beam, particularly without low intensity or dark spots at different beam spreads. Such a lamp should also require lower maintenance than other metal halide lamps presently available.